scholarly journals Combined method of opencast and underground mining of valuable ore

2018 ◽  
Vol 56 ◽  
pp. 01023
Author(s):  
Niyaz Valiev ◽  
Vyacheslav Berkovich ◽  
Vladimir Propp ◽  
Konstantin Kokarev

The efficiency of the combined opencast and underground mining of deposits directly depends on the overburden amount within the open pit boundaries. The amount of overburden to be removed, in its turn, is determined by the angles of the open pit slopes. At the same time, the influence of the open pit slope angle on the amount of the rock mass within the open-pit contours increases in an arithmetic progression with the mining depth. This fact confirms the direct relationship between the open pit slope angle and the efficiency of the mining operations from both an economic and ecological points of view. The article considers the technology for mining steeply inclined deposits of valuable ores by means of underground chambers mined out in advance with consolidating stowing to support unworked sides of an open pit called “well”. The chambers which can be not only vertical but also inclined at an angle of 60-80° serve to create an artificial fence (a ring concrete support). The work of the fence supporting the open pit side is markedly different from that of retaining walls of any type since the consolidating stowing mixture used to create the fence provides an ideal contact of the concrete wall with the enclosing rocks, thus making it impossible for an artificial fence to overturn. The proposed combined mining technology is expected to reduce considerably the number of the overburden operations, to minimize the damage caused by mining operations to the environment, and to increase the intensity of mine workings.

Author(s):  
V. A. Cherepanov ◽  
I. A. Glebov

The questions of improving the technology of completion of deposits are closely associated with an increase in the efficiency of technological processes and introduction of new methods and means of mechanization, optimization of process parameters to minimize the cost and increase the intensity of mining works in conditions of changing parameters of the working area depth of mining. For different conditions of completion of deposits by open-underground method, depending on the volume of traffic and parameters of quarries, it is proposed to use the appropriate underground transport workings. Optimization of the parameters of the sides of the quarry allows to increase the slope angle and increase the cost-effective depth of open-pit development. As one of the possible ways of refining deposits, the use of inclined underground transport workings is proposed by developing a quarry with a tunnel opening zone, or using underground mining operations, but without building capital vertical shafts. The article presents the factors that influence the opening scheme deep horizons of quarries with the use of sloping underground transport development with using articulated trucks and road trains. The factors are the basis for further search of rational parameters of openunderground technology of completion of instrument and sub-barrier reserves. To assess the depth of the transition to the opening scheme using the tunnel opening zone, it is necessary to take into account a number of factors: mining, technical, and economic. The results of such calculations are given in the article. The application of the proposed technology will increase the completeness of field development due to the involvement in the development of instrument and sub-barrier reserves, which is an urgent task in connection with the upcoming achievement of the stage of completion of deposits at many mining enterprises, both in the near future and in the long term.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Rongxing He ◽  
Jing Zhang ◽  
Yang Liu ◽  
Delin Song ◽  
Fengyu Ren

Continuous mining of metal deposits leads the overlying strata to move, deform, and collapse, which is particularly obvious when open-pit mining and underground mining are adjacent. Once the mining depth of the adjacent open-pit lags severely behind the underground, the ultimate underground mining depth needs to be studied before the surface deformation extends to the open-pit mining area. The numerical simulation and the mechanical model are applied to research the ultimate underground mining depth of the southeast mining area in the Gongchangling Iron mine. In the numerical simulation, the effect of granular rock is considered and the granular rock in the collapse pit is simplified as the degraded rock mass. The ultimate underground mining depth can be obtained by the values of the indicators of surface movement and deformation. In the mechanical model, the modified mechanical model for the progressive hanging wall caving is established based on Hoke’s conclusion, which considers the lateral pressure of the granular rock. Using the limiting equilibrium analysis, the relationship of the ultimate underground mining depth and the range of surface caving can be derived. The results show that the ultimate underground mining depth obtained by the numerical simulation is greater than the theoretical calculation of the modified mechanical model. The reason for this difference may be related to the assumption of the granular rock in the numerical simulation, which increases the resistance of granular rock to the deformation of rock mass. Therefore, the ultimate underground mining depth obtained by the theoretical calculation is suggested. Meanwhile, the surface displacement monitoring is implemented to verify the reasonability of the ultimate underground mining depth. Monitoring results show that the indicators of surface deformation are below the critical value of dangerous movement when the underground is mined to the ultimate mining depth. The practice proves that the determination of the ultimate underground mining depth in this work can ensure the safety of the open-pit and underground synergetic mining.


2021 ◽  
Vol 315 ◽  
pp. 01006
Author(s):  
Tatiana Tyuleneva ◽  
Roman Shishkov ◽  
Elena Kucherova ◽  
Marat Moldazhanov

In recent years, there has been a decline in the efficiency of coal mining by traditional methods. On the one hand, the volume of coal outside the contour of the cut, which is economically impractical for open-pit mining, is increasing. On the other hand, when using underground geotechnology, the cost of production exceeds the cost of performing mining operations using open geotechnology, this is due to differences in the factors of operation of the open pit and the mine. This circumstance determines the use of open-underground technology for mining coal reserves outside the contour of the open pit as an actual and promising direction. This article describes a methodological approach based on the use of technological schemes for the preparation and treatment of reserves of powerful shallow coal seams, the justification of the parameters of combined geotechnology with a coordinated and balanced development of open and open-underground mining operations with the distribution of reserves for open and open-underground mining of coal reserves beyond the limit contour of the open pit, the preparation of excavation sites directly from its workings and the coordination of production capacity and the speed of their development. Its application will increase the production capacity of the coal mining complex without additional environmental burden and will provide an increased return on investment.


2013 ◽  
Vol 634-638 ◽  
pp. 3277-3281 ◽  
Author(s):  
Shi Guo Sun ◽  
Hong Yang ◽  
Chun Sheng Li ◽  
Bao Lin Zhang ◽  
Jia Wang ◽  
...  

The stability state of slope rock mass is relating to each other’s relative location during the transformation from open-pit to underground mining, it’s the most disadvantageous influence on the slope stability when the underground mining area is located in the toe of slope, and it’s the best influence as in the slope extracellular region. Slope stability factor changes with the geometric dimensions of underground mining increased, but not in direct proportion. Under the condition of constant geometric dimensions of mining area, the influence on slope stability is changing with the mining depth increased. Thus indicating that the influence on slope stability by underground mining has its spatial property, and to determine the specific influence value requires a combination of many factors, such as the relationship of relative spatial position, the geometric dimensions of mining area, engineering geological conditions and so on.


2021 ◽  
Vol 44 (4) ◽  
pp. 358-368
Author(s):  
B. L. Talgamer

It is in 1930 that the training of mining engineers began in Eastern Siberia on the basis of the Siberian Mining Institute (now Irkutsk National Research Technical University). In 1931 the Department of Mining Arts was organized, which later was named the Department of Mineral Deposits Development. Over the years, the Department has trained more than 7000 graduates – mining engineers, who made a huge contribution in the development of the mining industry in the Irkutsk region and neighboring territories including Mongolia. The Department has trained more than a hundred mining engineers and Masters of science for Mongolia; assisted the lecturers and professors of the Mongolian Polytechnic University (now Mongolian University of Science and Technology) in organizing the educational process for training specialists for the country's mining industry. At its different formation stages the Department of Mineral Deposits Development was headed by well-known scientists – mining engineers, who created three scientific schools for the development of coal, placer and gold deposits; the obtained scientific results were marked with two State awards of the Russian Federation, dozens of doctoral and candidate dissertations were defended and about 100 patents were received. Today, the Department super- vises the training of mining engineers in open-pit and underground mining of mineral deposits, carries out a large amount of research and design work on the orders from mining enterprises, trains academic staff, develops new technologies and technical solutions in order to improve mining operations. The Department is deeply involved in the cooperation with mining enterprises, research and design organizations, as well as with universities that train mining engineers.


Author(s):  
S.B. Kulibaba ◽  
◽  
E.V. Fedorov ◽  

Conditions for the coal extraction under the built-up areas and natural objects in the Russian Federation are fully regulated by the Rules for the protection of structures and natural objects from the harmful effect of the underground mining at the coal deposits. Determination of the degree of danger of effecting mining operations on these objects, and the choice of measures for their protection are carried out based on the calculation of the earth surface deformations. The purpose of the work is to develop proposals for the modernization of the current regulatory and methodological document based on the analysis of the compliance of its provisions with the modern conditions of the deposits underground mining. Experience of applying the document under consideration in the modern conditions of the development of coal deposits showed that many of its provisions contain a number of inaccuracies, in particular: ambiguity in determining the boundaries of the zone of dangerous influence of the underground mining; lack of a methodology for predicting the period of damping of the process of earth surface damage after stopping the working face; limited conditions for determining the standard deformation indicators for civil buildings, etc. In addition, in this document, only the underground method of mining coal seams is considered, while the more promising is a combined development, combining underground and open-pit methods. The problem of inconsistency of the current rules provisions with the modern conditions can have a very negative effect on the safe state of the undermined objects. Based on the analysis of the identified shortcomings, a number of proposals for improving the rules was developed. In particular, it was proposed to expand them by including the rules and regulations of the combined method of deposits development. It is also required to update the normative and methodological parts of the document bringing them in line with the modern conditions of deposit development considering the accumulated experience of the objects undermining, and the results of the latest studies of rock mass deformation.


2021 ◽  
pp. 43-47
Author(s):  
K. Sanakulov ◽  
N. P. Snitka

The international geological community has acknowledged Muruntau gold deposit as the greatest discovery in the mid-to-late 20th century. Muruntau mine field holds the total appraised resource potential of more than 4.5 thousand tons of gold. Hydrometallurgical plant GMZ-3 implements gold-ore processing by gravitational sedimentation and adsorption. The technological and instrumental modernization of the gold processing circuit toward its higher capacity, gold recovery and thoroughness are the important aspects of production improvement and cost reduction. The developed and introduced ore milling flowchart provides replacement of the second milling stage pumps by higher-capacity pumps backed up with additional cyclones. Aiming to ensure stable gold production at plants GMZ-2 and GMZ-3, Navoi MMC’s experts accomplished the feasibility study of mining operations in Chukurkuduk and Turbai deposits in 2020. The growth prospects for open pit mining in Murunatu–Myutenbai fields after 2060 are estimated using the model of optimized ultimate pit limit design at the gold price of USD 1500/t. The model ultimate pit limit embraces all probable reserves as per the detailed 2D seismic data as of early 2020, including proven reserves intended for open pit and underground mining. The gold ore appraisal and the expansion program elaborated for Muruntau gold mining and refining integrated works in joint Muruntau–Myutenbai field, through implementation of operation phases V and further make it possible to forecast stable performance up to 2030–2050.


2012 ◽  
Vol 594-597 ◽  
pp. 70-75
Author(s):  
Shi Guo Sun ◽  
Hong Yang ◽  
Chun Sheng Li ◽  
Bao Lin Zhang ◽  
Ai Wei Miao ◽  
...  

During turning open-pit into underground mining, the state of slope stability is related to the relative space positional relationship between open-pit mining and underground mining. The toe area of slope is the most unfavorable area to slope stability and the outer region of slope is the most favorable area, while the central area of the slope has the most complicated effect on slope stability so that the mechanism of its influence can be understood only by the means of calculation. The slope stability coefficient decreases with the augment of underground mining geometric dimension. But it remains constant when the underground mining area is fully extracted. With the increase of mining depth, its range of influence on slope stability increases, which results in the decrease of slope stability coefficient. However, the slope stability coefficient tends to unchanged when the mining depth increases to some certain value.


2018 ◽  
Vol 41 ◽  
pp. 01041
Author(s):  
Vladimir Makarov ◽  
Péter Kovacs ◽  
Samuel Dagmar ◽  
Riccardo Paulman

The main sources of environmental pollution are: pollution from the residual effects of working out of mine fields by underground method; pollution from secondary mining of mine fields by the open method. The pollution of the environment from the underground mining of mine fields is mainly due to the erosion of the surface of the ditches caused by collapse of the underground workings, spontaneous combustion of the remaining coal reserves and exit of poison gases SO2 and CO to the surface through the cracks from the lower horizons of the worked-out mine fields. This makes actual the research of technological possibilities of harmful emissions reducing when quarrying underground mines’ fields. The environment deterioration from conducting open pit mining operations in the underground mine fields is caused by the technological processes of quarrying (preparation of rock for excavation, excavation, transportation of rocks and coal, dumping), by the objects of the open pit infrastructure (industrial site, transport communications, trenches and other workings, coal storage and rock dumps). The main direction of eliminating the negative environmental consequences of underground mining is the localization or complete isolation of the underground mines influence’ on the surface.


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